Tinea indecisiva is characterized by concentric scaly rings simulating tinea imbricata but caused by dermatophytes other than Trichophyton concentricum.
Tinea indecisiva has been rarely reported. We report a unique case and review of the previously reported cases, pathogenesis, and management.
An adult Indian man developed extensive tinea cruris and tinea corporis with concentric rings of scaly lesions over the groin, buttocks, and thighs following the use of oral corticosteroids and antifungal-steroid cream for 3 months. Mycologic and immunologic studies were performed for diagnosis.
Diagnosis of tinea indecisiva was confirmed on the appearance of "ring-within-a-ring" lesions clinically and isolation of Trichophyton mentagrophytes var. interdigitale as the etiologic agent on mycologic testing. Intradermal testing with Trichophyton extract showed fluctuating hypersensitivity responses. Four-week treatment with daily oral terbinafine resulted in complete resolution.
Tinea indecisiva should be considered in a patient with tinea imbricata-like lesions with local immunosuppression caused by a non-concentricum dermatophyte.